Eyeleted bulk spacer assembly



June 28, 1960 M. D. FORTE EYELETTED BULK SPACER ASSEMBLY Filed July 22. 1958 INVENTOR. MICHAEL D. Fum'E 2 343,224 EYELE'IED BULK SPACER ASSEMBLY Michael D. Forte, East Petershurg, Pa.,iassignor to Radio This'invention relates to theamounting' of' a unitary electrodecage in the envelope of an electron tube and particularly to a spring-type-bulbspacer assembly eyeleted to an insulator plate of the cage for providing an extremely ruggedized electron tube.

i Certain electron tubes include unitary electrode cages wherein the tube electrodes are mounted between a pair of insulator plates, e.g., mica. For use in some applications such cages must be securely mounted within the envelope of the tube so as to dampen cage resonances and to withstand severe impact shock without damage to any of the tube parts or without upsetting the relative spacings thereof. However, when it is desired to use mica as the insulator plates between which the tube electrodes are mounted, difiiculties are encountered due to the fragility.

of mica and its tendency to flake and crumble when subjected to repeated scrapping or pounding against other of the 'tubeparts.

Accordingly, it is an object of this invention to provide a novel and improved spring-type bulb spacer assembly which is securely fixed to one of the insulator plates of the tube cage so as to be extremely resistive to any bending, twisting, or pounding forces due to impact shock, and yet which is economical to make.

In the drawings:

Fig. 1 is a perspective view of an electron tube iii- 'corporating the invention;

Fig. 2 is an enlarged plan view of a portion of the tube of Fig. 1 illustrating the novel and improved springtype bulb spacer assembly according to my invention; and

Fig. 3 is an elevation view partly in section of a portion of the novel and improved spring-type bulb spacer assembly of Fig. 2.

Fig. 1 illustrates an electron tube comprising a unitary electrode cage 12 enclosed by a vacuum envelope 16. The electrode cage 12 includes a pair of mica plates 18 and 20 between which a tubular anode 22 and other electrodes contained within the anode and not shown are mounted. The electrode cage 12 is supported by both a plurality of lead-ins 24 sealed through one end of the envelope 16 and a single lead-in 26, which connects to the anode 22, sealed through'the opposite end.

According to my invention the cage 12 is supported against lateral movement within the envelope 16 by a plurality of spring-type bulb spacer assemblies 28. The bulb spacer assemblies 28 are attached to and around the periphery of the mica plate 18 and include a slotted, U-shaped leaf-spring 30 secured to a pin 32 which is in turn secured through the mica plate 18 by a novel eyeleted construction according to my invention. By mounting the spring 30 on the eyelet and pin assembly, relative scrapping motion between the spring and the mica plate 18 is prevented. Thus, notwithstanding the destructibility of mica, a more durable cage mounting arrangement is provided. Figs. 2 and 3 illustrate more fully the nature of the eyeleted construction.

In Figs. 2 and 3 one of the bulb spacer assemblies 28 is rates Patent mount 'the eyelet 34 in the aperture of the mica plate 18.

ice

shown to comprise an elongated tubular eyelet 341disposed through an aperture in themica plate 18. The,

eyelet 34 includes an. elongated straight. tubular portion- 36 witha flat radial. flange'38 at one end thereof. A washer 40' is disposed around thetubular portion 36 of the eyelet 34 and flatly abutted' against the mica'plate 18. The tubular portion 36 ofthe eyelet is longitudinally splitinto a plurality of circumferential sections 42.; Selected ones. only of the circumferential sections are bent'back and crimped against the washer 140 to securely By crimping only some of the circumferential sections; 42 back against the'washer 40,;a considerable amount of the tubular portion 3610f the eyeletis. left intact to.pro-' vide a good support. andwelding surface for the pin :32 inserted therethrough. The pin '32 can befixed, to the eyelet 34 by spotfwelding against this remaining tubular portion 36 of the eyelet.

As illustrated in Figs. 1 and. 2, the spring 30 is centrally slotted throughout the base of its U and along aportion of the legs thereof such that the spring can be disposed with the mica plate 18 extending into the slot 44..v

The spring 36' is provided with. a re-entrant'bend 46 at the base of the U which abuts against'the pin.32 and the remaining part. of the'tubular portion 36 of the eyelet to which it is aifixed.

It will be'appreciate'd that 'the'tubular portion-36 of the eyelet 34.provides an elongated pin receiving member which in turn prevents tiltingvor: turning of the pin .32.

relative to themica plate18. At thesame time a con-v venient Welding surface: is'also provided. 1

The addition of the washer 40 provides a rigid non destructible surface against 'which the crimped portion 42 of the eyeletmakes contact. Such a structure protects the mica from damage due to eyelet scoring which might be produced by twisting or bending of the eyelet relative to the mica plate 18. As previously mentioned, mica, in having the tendency to flake and crumble, cannot adequately engage with a small crimped edge without damage thereto. Moreover, not only does the washer 40 provide a non-destructible area for the crimped portion 42 to contact, but it also results in strengthening themica plate 18 near the aperture therethrough'against forces parallel to the pin 32. For this reason the addition of the washer 40 results in an eyeleted assembly which is quite resistive to bending forces applied thereto and which will not become loose with repeated shock vibrations. Should the alternative of the washer 40 be provided by crimping the entire tubular portion 36 of. the eyelet 34 against a bare mica plate, as is the practice in conventional riveting, no elongated pin receiving portion 36 would be provided to give a rigid support to, or welding surface for, the pin 32.

Thus, it will be appreciated that, according to my invention, crimping of only circumferential sections of a split eyelet against a washer results both in providing a support and welding surface for the pin and in securing the eyelet in the mica plate such that mica deterioration is avoided.

I claim:

1. A bulb spacer assembly for an electron tube comprising an apertured plate, an eyelet including an elongated tubular portion and a fiat radial flange extending therefrom, the tubular portion of said eyelet being disposed through said aperture with said flange flatly abutting said apertured plate on one side thereof, a pin extending through and supported solely by said eyelet, a bulb engaging member fixed to said pin and having a portion extending laterally therefrom beyond aperipheral region of said apertured plate, said portion being adapted to intercept a force tending to move said member in a direction to produce tilting of said pin with respect to posed around the tubular portion of said eyelet and flatly abutting said aperture plate on the otherside thereof; circumferential portions only of said tubular portion of said eyelet being bent back and crimped against said washer to secure said eyelet in said apertured plate.

2. A bulb spacer for an electron tube comprising an apertured plate, an eyelet assembly secured to said plate through said aperture, a pin extending through and secured to said eyelet assembly, and a spring mounted on said pin and eyelet assembly, said eyelet assembly com-i prising an eyelet including an elongated tubular portion longitudinally split into a plurality of circumferential sec tions and a radial flange extending therefrom, a'washer disposed around said tubular portion. parallel to said flange with said apertured plate sandwiched between said flange and said washer, selected ones of said circumferential sections being bent back and crimped against said washer, said pin engaging and being fixed only to said eyelet and said spring. 1

3. An electron tube bulb spacer assembly comprising an insulator plate having an aperture therethrough, an elongated tubular eyelet having a flat radially extending flange, said tubular eyelet being disposed through said aperture with said flange flatly abutting said apertured plate on one side thereof, an annular flat washer disposed around the tubular portion of said tubular eyelet and flatly abutting said apertured plate on the other side thereof, circumferential portions of said tubular portion of said tubular eyelet being crimped back and against said washer, a pin extending through said tubular portion of said eyelet and fixed thereto, said pin engaging and being supported solely by said eyelet, a U-shaped spring having a slot extending centrally thereof throughout the U thereof, said spring being disposed with an edge of said apertured plate extending within said slot and the ends of said spring extending outward of the periphery of said apertured plate, said spring contacting and being fixed to said pin at the base of the U of said spring.

4. A bulb spacer assembly for securing a unitary electrode cage within an enclosing envelope of an electron tube comprising a mica plate having an aperture therethrough adjacent to the periphery thereof, an elongated metal eyelet having a tubular portion and a flat radial flange larger than said aperture extending therefrom, said eyelet being disposed through said aperture, an annular fiat metal washer disposed around the tubular portion of said eyelet and flatly abutting said apertured mica plate on the other side thereof, circumferential portions of said tubular portion of said eyelet being bent back and crimped against said washer to secure said eyelet in said apertured mica plate, a metal pin extending through said tubular portion of said eyelet and fixed thereto, said pin engaging and being supported solely by said eyelet, a U-shaped spring having a slot extending centrally thereof, said spring being disposed with an edge of said apertured mica plate extending within said slot and the ends of said spring extending outward of the periphery of said apertured mica plate, said spring contacting and being fixed to said pin at the base of the U of said spring.

5. An assembly for securely spacing a unitary electrode cage relative to the enclosing envelope of an electron tube, said assembly comprising a mica plate having 'an aperture therethrough adjacent to the periphery thereof, an elongated eyelet having an elongated tubular portion and a flat radial flange extending therefrom, said tubular portion of said eyelet being longitudinally split into a plurality of circumferential sections, said eyelet being disposed through said aperture with said flange flatly abutting said apertured mica plate on one side thereof, an'annular flat metal washer disposed around. the tubular portion of said tubular eyelet and flatly abutting said apertured mica plate on the other side thereof, only some of said circumferential sections of said tubular portion of said eyelet being bent back and crimped against said washer to secure said tubular eyelet in said apertured mica plate, a metal pin extending through said tubular portion-of said eyelet and fixed thereto, a U-shaped spring slotted centrally throughout the base and a portion of each leg thereof and disposed with said apertured mica plate extending into said slot and the ends of said spring extending outward of the periphery of said apertured mica plate, said spring contacting and being fixed to said pin at the base of the U of said spring, said pin being engaged only by said eyelet and said spring.

6. An eyelet assembly comprising an apertured plate, an elongated tubular eyelet having a radial flange extending therefrom, the tubular portion of said eyelet being longitudinally split into a plurality of circumferential sections, said eyelet being disposed through the aperture of said plate with said flange flatly abutting one side of said plate around said aperture, a pin extending through and fixed to said eyelet, a shock absorbing member fixed to said pin and having a free end portion extending laterally from said pin, whereby forces applied to said free end portion tend to tilt said pin, and means for preventing tilting of said pin in response to said forces, said means including a washer disposed around the tubular portion of said eyelet and flatly abutting the other side of said plate around said aperture, selected ones only of said circumferential sections being bent back and against said washer to secure said eyelet in said apertured plate.

References Cited in the file of this patent UNITED STATES PATENTS 

